Rapid Prototyping Machine Research Articles

OP108: Precise reconstruction of jaws assisted with digital surgical technique

Purpose The digital surgical technique (DST) including virtual design, stereomodel operating and surgical navigation was used for jaw reconstruction with microvascular fibula and iliac flap in order to find an effective way to reach more accurate outcome of reconstruction. Materials and methods Based on the CT scan data, the entire process of the lesion resection and reconstruction were simulated using the 3D software to select the most feasible plan. According to the results obtained from software, the simulated operation was performed on the stereomodels of skull and fibula/iliac formed by the rapid prototyping machine, including the manufacture templates and prebending of titanium plates. The whole operation was performed guided by the surgical navigation system. Results There were 20 reconstructed cases using this technique and the successful rate of the flap transfer was 100%, which indicated that a good clinical outcome in terms of facial contour and occlusion. CT scan showed the reconstructed profiles were ideal. The error of important corresponding points in the image registration was 2–4 mm. Conclusions For the jaw reconstruction, DST is of considerable value for the accurate planning and precise performance for reconstruction of jaws, and the result of reconstruction of jaws will be more predictable and stable assisted with DST.

Innovative Vacuum Cleaner Design Using TRIZ Method

Existing intelligent vacuum cleaners were found to have inadequate suction and power consumption issues in addition to an undistinguished appearance. Therefore, this studys aim was to explore and improve the functionality and appearance of intelligent vacuum cleaners. Based on TRIZ theory, this study conducted a function analysis of intelligent vacuum cleaners and established a proposal for improvement. By combining the 39 engineering parameters with the TRIZ contradiction matrix and 40 inventive principles, appropriate rules were chosen to improve the problem of innovation. At the same time, through patent review and analysis, a design method which did not infringe on current patents was developed. In the results of this study, the vacuum cleaner was complied with an innovative UFO-like design, with suction ports set around the chassis to increase cleaning range and efficiency. When the battery power is below the minimum requirements for optimal performance, the vacuum cleaner can automatically return to a charging stand and replace its own battery. This study also designed the joystick and buttons of the remote control to resemble a cute alien for improved aesthetics. In conclusion, this study used Pro Engineering software to design a vacuum cleaner like UFO and a remote controller shaped like an alien, and a rapid prototype machine was employed to create a product prototype.

Computer Aided Reverse Engineering of Machine Parts

One of the methods to decrease the technology gap between different countries and to transfer complex technologies is reverse engineering. In Reverse engineering of mechanical parts it becomes necessary to obtain a geometric model of a part either to modify the existing design or to analyze it using schemes such as the Finite Element Method (FEM). Theobjective of this work is to develop and construct the solid model of an existing machine part by the geometric analysis of three copies of this part. Shape and dimensions of the part are obtained using laser scanner arms and the probing mechanism of a Coordinate-Measuring Machine (CMM). Segmentation & surface fitting are conducted using Geomagic Studio 12 software and the solid models as well as the workshop drawings are generated on UGS NX 7.5 CAD software. Material analysis and mechanical testing are performed to identify the polymer from which the part is produced. The prototype of this part is constructed Using 3D rapid prototyping machine using the STL file of the produced CAD solid model. The final results of this work are the construction of the complete solid model of the part with all its features and dimensions as well as its material using reverse engineering techniques.

‘Visionary rather than practical’: craft, art and material efficiency

Emotional responses to materials and manufactured objects have a long history but provoked vivid writing during the design reform debates of the nineteenth century and were carried forward into the twentieth century. In particular, nineteenth-century anxieties about plasticity and about composite materials are still with us. Wood continues to represent sustainability, 'truth to materials', emotional durability and an assumed reassuring contact between material, tools and maker. By contrast, the facture offered by new media, in the form of self-replicating rapid prototyping machines, appears disembodied while also offering the possibility of homesteader-making. The desirability of recycling and up-cycling is currently central to our emotional responses to materials, with the world's waste dumps becoming sites of horrified fascination and inspiration. Symbolic moves in the direction of autarchy and reverse engineering by artists and designers register doubts about sustainability and seek to uncover the hidden impact of individual materials. This survey of historic and current attitudes towards materials and making processes by makers, artists and designers sheds light on anxieties familiar to us all, concerning technological development, authentic experience, agency, a sense of selfhood and the often bruising experience of modernity itself.

Use of patient-specific templates in hip resurfacing arthroplasty: experience from sixteen cases

Hip resurfacing arthroplasty (HRA) is a technically demanding operation, requiring both accuracy and precision in placement of the acetabular and femoral components. Malalignment of the component can lead to notching and possible femoral neck fractures. We used specific templates created using a rapid prototyping machine based on the patients' anatomy, to aid in accurate intraoperative pin placement. A 3D model of the hip was reconstructed using spiral computed tomography (CT) data by Amira 3.1 software in 16 patients in whom HRA was planned for hip osteoarthritis (OA). All of the patients in the study had normal contralateral hips. The rotational centre of femoral head on the normal side was superimposed using Imageware12.0 software to determine the centre of the femoral head on the contralateral side. The data was then used to produce patient-specific templates using a rapid prototyping technique. These templates were designed according to the anatomical features of femoral head surface, the rotation centre and the planned prosthesis shaft angle. The orientation of the prosthesis was determined by matching the model to the femoral head surface during the operation. In addition, a control group of 18 patients with OA was operated upon by the conventional method. The mean prosthesis stem shaft angle (SSA), as determined from postoperative imaging, was 138.68 ± 8.85° for the locating template group, and (118.9 ± 12.8) for the conventional group. The locating template designed and constructed preoperatively can provide precise and dependable location for hip resurfacing femoral components during arthroplasty and ensure the valgus stem placement necessary for optimal outcomes.

Research and Realization of a New Algorithm for Stereo Matching Based on Binocular Vision

In the development of a three-dimensional measurement system, binocular stereo matching is the most important and difficult. In the basis of introducing selective principles of matching algorithm, a new stereo matching algorithm for binocular vision is put forward that is named noncoded difference measuring distance. The algorithm effectively grapples with the problem of searching for the coincidence relation of raster and can efficiently and accurately obtain three-dimensional world coordinates of the entities. Experiment results show that this 3D measuring machine can effectively measure the 3D solid profile of free surface. During the evaluation test for accuracy, scan a standard plane. Fit all 3D points in one plane, and then the flatness value of this plane is obtained. The flatness value of the standard plane has been ultimately measured as: ± 0.0462mm, this measuring accuracy can completely satisfy the requirements of rapid prototyping or CNC machining, it as well as achieves the stated accuracy (± 0.05mm).

Rapid Prototyping Machine in Teaching Practice and Application

In order to adapt need of market economy development,to shorten the product development cycle,improve the ability to manufacture complex parts,rapid prototyping manufacturing technology to become a new direction in the development of the manufacturing industry,many colleges and universities have carried out the rapid prototyping manufacturing research, mechanism, material professional college students will become the main force to promote technology applications.Will therefore rapid prototyping machines used in teaching training segment, to standardize the experimental behavior of the students, played an important role in the overall quality of training of students and improve ability.

Making graphics tangible

This is a write-up of material presented at keynote talks at Virtual Reality 2012 and at Shape Modeling International 2012. Producing tangible, physical output becomes a growing role for computer graphics due to the emergence of inexpensive rapid-prototyping machines and on-line fabrication services. While producing small models with a layered manufacturing process has become very easy, creating larger and more durable objects still requires a designer to address an expanded list of issues. In this paper some of these issues are discussed based on experiences the author has gained while designing various physical artifacts ranging from mathematical visualization models and geometrical puzzles to large scale sculptures. Tangible artifacts also gain importance at the beginning of a design process and as input to computer graphics tools. An argument is made and an outline is given for new ways and better user interfaces to enter the geometry of inspirational artifacts into our virtual CAD environments.

Field Performance of Point Velocity Probes at a Tidally Influenced Site

AbstractConventional methods to estimate groundwater velocity that rely on Darcy's Law and average hydrogeologic parameter values are insensitive to local‐scale heterogeneities and anisotropy that control advective flow velocity and direction. Furthermore, at sites that are tidally influenced or have extraction wells with variable pumping schedules, infrequent water‐level measurements may not adequately characterize the range and significance of transient hydraulic conditions. The point velocity probe (PVP) is a recently developed instrument capable of directly measuring local‐scale groundwater flow velocity and direction. In particular, PVPs may offer distinct advantages for sites with complex groundwater–surface water interactions and/or with spatially and temporally variable groundwater flow conditions. The PVP utilizes a small volume of saline tracer and inexpensive sensors to directly measure groundwater flow direction and velocity in situ at the centimeter‐scale and discrete times. The probes are installed in conventional direct‐push borings, rather than in wells, thus minimizing the changes and biases in the local flow field caused by well installation and construction. Six PVPs were installed at a tidally influenced site in North Carolina to evaluate their implementability, performance, and potential value as a new site characterization tool.For this study, a new PVP prototype was developed using a rapid prototyping machine (i.e., a “three‐dimensional printer'') and included both horizontally and vertically oriented tracer detectors. A site‐specific testing protocol was developed to account for the spatially and temporally variable hydraulic conditions and groundwater salinity. The PVPs were tested multiple times, and the results were compared to the results of several different groundwater flux and velocity estimation tools and methods, including a heat‐pulse flowmeter, passive flux meters, single‐well tracer tests, and high‐resolution hydraulic gradient analysis. Overall, the results confirmed that the PVP concept is valid and demonstrated that reliable estimates of groundwater velocity and direction can be obtained in simple settings. Also, PVPs can be successfully installed by conventional methods at sites where the formation consists primarily of noncohesive soils and the water table is relatively shallow.Although some PVP tests yielded consistent and reliable results, several tests did not. This is likely due to the highly transient flow conditions and limitations associated with the PVP design and testing procedures. PVPs offer particular advantages over, and can effectively complement, other groundwater flow characterization techniques for certain conditions, and objectives may be useful for characterizing complex flow patterns under steady conditions; however, this study suggests that PVPs are best suited for conditions where the flow hydraulics are not highly transient. For sites where the hydraulic conditions are highly transient, the most reliable approach for understanding groundwater flow behavior and groundwater–surface water interactions would generally involve both a high‐resolution hydraulic gradient analysis and another local‐scale method, such as tracer testing. This study also highlighted some aspects of the current PVP design and testing protocol that can be improved upon, including a more robust connection between the PVP and injection line and further assessment of tracer solution density effects on vertical flow. © 2013 Wiley Periodicals, Inc.

Open Source Powder based Rapid Prototyping Machine for Ceramics

3DP (Three Dimensional Printing) technology is one of the SFF (Solid Freeform Fabrication) technologies which have recently come into the spotlight due to its adaptability to various applications. However, commercial 3DP machines are limited as to the use of building material, without voiding the warranty on the machine.At the same time, a rise in domestic rapid prototyping machines is observed, but none of these machines use the 3DP process. Therefore, an open source 3DP machine is designed and built. In this study, the machine is discussed and the first experiments are carried out to create ceramic (alumina and zirconia) membranes with specific physical properties.The purpose for developing this machine was opening up the opportunity to investigate printing ceramic membranes and reactors. Were, contrary to many other applications, maximal compaction of the powder during deposition is not desirable, to maintain an open structure the walls of the printed object. The machine is able to deposit the powder with adjustable bulk density, which is used to alter the properties of the membrane. The design of the printer (drawings, electronic layout, software) is publicly released under an open source license, free for others to adapt, build and use, e.g. in academic research.

Selective Laser Sintering of Bio-Metal Scaffold

This study presents a fabrication process of bone scaffold model with titanium biomedical materials by rapid prototyping (RP) technique. A RP machine with Nd:YAG laser (120W) was developed to produce bone scaffolds using a selective laser sintering (SLS) technology. The slurry state of biomedical material consists of titanium powder and silica sol mixed at 2g: 1g weight ratio was used in the proposed process. This biomedical titanium slurry was solidified after scanning by a laser beam. The process parameters of laser were tuned at a laser power of 15W, a frequency of 16KHz and a scanning speed of 100mm/s to build the titanium biomedical bone model within 3hrs. Experimental results show that the compressive strength was 142MPa after post treatment at 900. The mechanical strength of these titanium biomedical material specimens by post sintering process is enhanced. Using this RP machine of layer additive processing, a bone scaffold with complex shape structure can be constructed. Therefore, this process has a greater potential for fabrication bio-metal bone scaffold in tissue engineering.

Three-dimensional superhydrophobic structures printed using solid freeform fabrication tools

Superhydrophobic surfaces are of fundamental and commercial interest as water does not wet the surface, leading to unique properties such as low slip angle, high contact angle, and icephobicity. These behaviours are achieved through a combination of low surface energy materials and high surface roughness. Two printing techniques were used to fabricate hydrophobic polymers into superhydrophobic surfaces. In one approach, a commercially available multi-jet modelling rapid prototyping machine was used to fabricate 3D superhydrophobic objects including helical conduits and porous membranes, using the standard printer resins. A robotic dispensing tool was also developed that enables greater freedom of material selection and feature shape. Both approaches were used to fabricate arrays of high aspect ratio surface features on which water assumes a nearly spherical shape and easily rolls off the surface at low tilt angles. The fabrication and wetting properties of surfaces made using these two techniques will be discussed.

Research on the Data Segmentation Technique of Large Rapid Prototyping Sample Based on Features

Because of the small workbench molding size of rapid prototyping equipment, the processing of large rapid prototyping samples is a problem during the new product development process, for example, motorcycle covering. The relative merits of accuracy engraving technique and rapid prototyping technique during processing are discussed. The method combining accuracy engraving machine and rapid prototyping machine to processing new motorcycle cover samples is proposed. And the surface data segmentation technique based on features is adopt to divide the large rapid prototyping sample reasonably, and then the small parts are collaged after respectively processing, so the problem of large rapid prototyping sample cannot once molding is solved, the speed of new product development is accelerated, the cost of new product development is decreased, the rapid manufacturing is realized. This method has been applied to the processing of new motorcycle cover samples and the application method is expounded.

Aerosol Deposition in a Nasopharyngolaryngeal Replica of a 5-Year-Old Child

Particle deposition in a child's nasal cavity is much different than that in the nasal airway of an adult because of the differences in geometry and breathing patterns. However, most deposition studies have focused on adults, and only a limited number of studies have been reported in a child's nasal cavity. This study was conducted as an in vitro test and computational fluid dynamics (CFD) analysis of particle deposition in the nasal replica of a 5-year-old child; both total and regional depositions were evaluated. The geometry of the nasal replica was based on magnetic resonance images of the head of the child. The replica was made by a rapid-prototyping machine. Monodisperse oleic acid and polystyrene latex aerosols ranging in size between 1 and 20 μm were delivered into the replica at flow rates of 10 and 20 L/min. Results showed that the total deposition from the in vitro experiments and CFD predictions matched to a high degree. Good agreement was also obtained when results were compared to existing i...

Research on the Model Reconstruction and Rapid Prototyping of Lumbar

Apply the rapid prototyping in the 3D reconstruction of solid model of lumbar. By separating the original CT image data according to threshold value, filling and repairing the hole and generated the STL file of lumbar, using Geomagic and UG NX software to complete the model of intervertebral disc and assembly of lumbar. Finally, the model was manufactured through FDM Vantage i rapid prototyping machine.

Discussing for a Rapid & Flexible Casting Design Method Based on Modeling, Simulation and Rapid Prototype Machine

Nowadays, customer has more and more requirements of quick product updating. On the opposition side, casting need a long lead time for tooling prepare and qualify. And a necessary test for casting is need. Whether a new casting design or existing casting product revised will take 16 weeks with tradition process. A new method raised in this text can help solute these problems. It calls Rapid & flexible process loop including CAD, CAE and RP. A better cost and time saving can be achieved via it.

Evaluation of the navigation system for orbital wall reconstruction in unilateral orbital fractures

To evaluate the efficiency of navigation system for orbital wall reconstruction in unilateral orbital fractures. Fifteen patients (7 male and 8 female) with unilateral orbital fracture underwent orbital reconstruction with the help of intraoperative navigation system. The average age was 34.3 ± 9.5 years. All patients underwent spiral CT scanning preoperatively, and the CT data was imported to the BrainLab navigation system (Germany, BrainLab company). The orbit of the intact side was mirrored to the opposite side as the reference for pre-operative planning. The titanium mesh was mounted on the resin template made by rapid prototyping machine based on the mirrored CT data. When the injury was limited, the hydroxyapatite sheet was used for the orbital wall reconstruction. During the operation, the real-time navigation helped to ensure precise placement. The re-establishing result was assessed based on the postoperative CT data with the following four variables: the volumetric difference between the bilateral orbit, the volume of the herniated soft tissue, the global projection and the discrepancy between the simulated and the achieved position of the reconstructed orbital wall. The reconstructive discrepancy was measured only in the titanium plate grafting cases. There were no serious complications such as infection, graft rejection and optic nerve injury in any case. Preoperatively, the average degree of enophthalmos was (3.5 ± 1.6) mm, the average volumetric difference between the injured and the unaffected orbit was (4.5 ± 1.8) ml, and the average volume of the herniated orbital soft tissue was (2.1 ± 0.7) ml. Postoperatively, the three values were respectively reduced to (1.3 ± 0.6) mm, (1.8 ± 0.9) ml and (0.7 ± 0.3) ml. The discrepancy of the medial and inferior wall were (2.5 ± 0.6) mm and (2.1 ± 0.4) mm. The intraoperative use of navigation system for the orbital wall reconstruction in unilateral orbital fractures can provide reliable accuracy and achieve satisfactory results.

Study of the Transmission System of Spreading Powder Device of Direct Metal Sintering Rapid Prototyping Machine

Direct metal sintering rapid prototyping mechanism is complex, including many kinds of transmission systems. Spreading powder device is important to direct metal sintering rapid prototyping mechanism. Based on grasping the working principle of the device, through the study of spreading powder device of direct metal rapid prototyping machine, grasp the process of spreading powder and the main structure of the device, and fabricate the simple model of the transmission system. In order to determine the necessary condition of how the spreading powder device functions, the dynamic parameters of the transmission system must be calculated, and the operation performance of the stepper motor must be checked. Then the precision and the processing quality of the finished part can be improved.

Moisture and Humidity Effects on the ABS Used in Fused Deposition Modeling Machine

The environment seems to have an effect on Acrylonitrile-Butadiene-Styrene (ABS) which consequently causes physical, morphological and thermal stability changes to the polymer. Not only that, these changes may have caused nozzle blockage on the liquefier of the Fused Deposition Modeling (FDM) rapid prototyping machine. Experiments are conducted to support and verify whether ABS does affect the blockage. It has been observed that physical changes may have not caused nozzle clogging.

Investment Casting – Rapid Tooling Approach

Investment casting is synonym with producing precision components and investment casters usually take up the order if the volume is huge enough. This is due to high and unjustifiable tooling cost and long lead times associated with the development of metal moulds for producing wax (sacrificial) patterns for customized single casting or small quantity production. One of the feasible solutions is opt rapid tooling. In so- called rapid investment casting the most critical process will be building the investment shell and protecting it from thermal crack. This work investigates the shell crack and counter. In this work pattern are modeled on rapid prototyping machine. During the ceramic shell preparation cracking is reported. Hence a remedy is explored as to control the thermal expansion of the pattern build material-acrylonitrile butadiene styrene (ABS) by using different build styles. Thermal expansion of five distinct styled ABS rapid samples were tested on Dilatometer. The investigation indicates the possibility of 63% reduction in thermal expansion of the pattern, which is very very encouraging.